I listened to it and the "I know for a fact" bit was the thing that caught me, "I speak to people". It's not a throwaway comment. It was the most interesting bit in that whole pod (which was a bit tedious). I take it that it either means he's lost the dressing room or they cannot execute what he's asking them to do. With the former, he's obviously not lost the players he has identified and brought in so he's got an insurance policy there. He's also promoted some young players who will likely stand by him and we see that they work really hard for the team when selected, so I have absolutely no worries about them (Garnacho, Mejbri, Gore, Pellistri). He drafted in Evans and was impressed by his personality, I think he'll be an asset to him in the dressing room and he'll likely be horrified by the culture that's within the club.
Someone here said he has to boot out the players he doesn't want. He tried that. Murtough and co. briefed the press numerous times this summer, even specified the required transfer fees (which was daft) but the club refused to take a hit (as with Maguire and the pay-off) or going up a gear in getting rid. That's a pretty crazy scenario, having all those players who are known to be unwanted and leaving the manager to deal with it.
If Mitten is talking about being able to carry out the tactical requirements, then that's something we have known since before he arrived. We knew which players would definitely not suit (de Gea, Maguire, and then the better players, like Bruno and Rashford, obviously Ronaldo too). The hope was that some of the better players would be able to adapt, and maybe they still can. They do however have to know they are not guaranteed their place, and in Rashford's case we have a major prospect vying for his place.
Anyhow, I thought this was interesting coming from Mitten. Hope he elaborates on it. He'll be reading this thread no question.